The inactivation of cytoplasmic malate dehydrogenase (L-malate: NAD+ oxidoreductase, EC 1.1.1.37) from porcine heart and the specific modification of arginyl residues have been found to occur when the enzyme is inhibited with the reagent butanedione in sodium borate buffer. The inactivation of the enzyme was found to follow pseudo-first order kinetics. This loss of enzymatic activity was concomitant with the modification of 4 arginyl residues per molecule of enzyme. All 4 residues could be made inaccessible to modification when a malate dehydrogenase-NADH-hydroxymalonate ternary complex was formed. Only 2 of the residues were protected by NADH alone and appear to be essential. Studies of the butanedione inactivation in sodium phosphate buffer and of reactivation of enzymatic activity, upon the removal of excess butanedione and borate, support the role of borate ion stabilization in the inactivation mechanism previously reported by Riordan (Riordan, J.F. (1970) Fed. Proc. 29, Abstr. 462; Riordan, J.F. (1973) Biochemistry 12, 3915-3923). Protection from inactivation was also provided by the competitive inhibitor AMP, while nicotinamide exhibited no effect. Such results suggest that the AMP moiety of the NADH molecule is of major importance in the ability of NADH to protect the enzyme. When fluorescence titrations were used to monitor the ability of cytoplasmic malate dehydrogenase to form a binary complex with NADH and to form a ternary complex with NADH and hydroxymalonate, only the formation of ternary complex seemed to be effected by arginine modification.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Investigating the binding of fluorescent probes to a trypanosomal-tRNA synthetase: A fluorescence spectroscopic and molecular dynamics study.
Arch Biochem Biophys
February 2025
Department of Biotechnology and Dr. B. C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, Kolkata, India. Electronic address:
Given the high prevalence of Chagas disease in the Americas, we targeted the unique arginyl-tRNA synthetase of its causative agent Trypanosoma cruzi. Among their many possible uses, naphthalene-derived fluorescent ligands, such as ANS and bis-ANS, may be employed in pharmacokinetic research. Although ANS and bis-ANS have become prominent fluorescent probes for protein characterization, the structural and spectroscopic characteristics of protein-ANS/bis-ANS complexes remain largely unknown.
View Article and Find Full Text PDFStructure, Function, and Activity of Small Molecule and Peptide Inhibitors of Protein Arginine Methyltransferase 1.
J Med Chem
September 2024
Pharmaceutical analysis Laboratory, College of Pharmacy, University of Manitoba, 750 McDermot Avenue West, Winnipeg, Manitoba R3E 0T5, Canada.
Protein arginine -methyltransferases (PRMT) are a family of -adenosyl-l-methionine (SAM)-dependent enzymes that transfer methyl-groups to the ω-N of arginyl residues in proteins. PRMTs are involved in regulating gene expression, RNA splicing, and other activities. PRMT1 is responsible for most cellular arginine methylation, and its dysregulation is involved in many cancers.
View Article and Find Full Text PDFOligomerization and a distinct tRNA-binding loop are important regulators of human arginyl-transferase function.
Nat Commun
July 2024
Department of Biochemistry, Case Western Reserve University, Cleveland, OH, USA.
The arginyl-transferase ATE1 is a tRNA-dependent enzyme that covalently attaches an arginine molecule to a protein substrate. Conserved from yeast to humans, ATE1 deficiency in mice correlates with defects in cardiovascular development and angiogenesis and results in embryonic lethality, while conditional knockouts exhibit reproductive, developmental, and neurological deficiencies. Despite the recent revelation of the tRNA binding mechanism and the catalytic cycle of yeast ATE1, the structure-function relationship of ATE1 in higher organisms is not well understood.
View Article and Find Full Text PDFA novel series of metazoan L/D peptide isomerases.
J Biol Chem
July 2024
Beckman Institute, University of Illinois, Urbana-Champaign, Urbana, Illinois, USA; Department of Molecular and Integrative Physiology, University of Illinois, Urbana-Champaign, Urbana, Illinois, USA; Institute for Genomic Biology, University of Illinois, Urbana-Champaign, Urbana, Illinois, USA; Department of Chemistry, University of Illinois, Urbana-Champaign, Urbana, Illinois, USA. Electronic address:
The function of endogenous cell-cell signaling peptides relies on their interactions with cognate receptors, which in turn are influenced by the peptides' structures, necessitating a comprehensive understanding of the suite of post-translational modifications of the peptide. Herein, we report the initial characterization of putative peptide isomerase enzymes extracted from R. norvegicus, A.
View Article and Find Full Text PDFAn Unbiased Proteomic Platform for Activity-based Arginylation Profiling.
bioRxiv
June 2024
Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis, St. Louis, MO 63110.
Article Synopsis
- Protein arginylation is a crucial posttranslational modification done by the enzyme ATE1, which involves adding an arginine to proteins, making it hard to distinguish from normal arginine present in proteins.
- Researchers introduced a new method called activity-based arginylation profiling (ABAP) that uses isotopic labeling to identify arginylation in various biological samples without interference from translational activities.
- ABAP successfully identified 229 unique arginylation sites in human proteins and can be applied to different samples, helping advance the understanding of this complex protein modification's biological roles.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!